Method and apparatus for charged aperture controlled electrostatic image reproduction

ABSTRACT

The invention relates to apparatus and methods for constituting or reproducing images through the use of a multi-layered screen consisting of an array of apertures from facsimile read-out arrangement. A propulsion field directs charged particles through the screen to a receiving medium preferably spaced at a distance from the screen. Charge distribution on the screen controls the flow of particles through the apertures, some of which are in effect blocked, partially blocked, unblocked, and enhanced, depending on the local charge level. Thus, it is possible to produce patterns of varying tone without contact with the printed or effected substrate. In the facsimile read-out arrangement the electrostatic charge pattern is laid down by a charging stylus through relative movement with the electrostatically chargeable multilayer screen. The screen may be flat or comprise a drum or other configuration and the insulative layer of the screen is preferably substantially non-light sensitive with print out made by passing charged particles through the stylus charged screen in accordance with signal modulation to paper wherein relative motion is established between the screen and paper.

United States Patent 1 Pressman et al.

[ Jan. 15, 1974 METHOD AND APPARATUS FOR CHARGED APERTURE CONTROLLED ELECTROSTATIC IMAGE REPRODUCTION [75] Inventors: Gerald L. Pressman, San Jose;

Thomas D. Kittredge, South San Francisco, both of Calif.

[73] Assignee: ElectroPrint Inc., Cupertino, Calif.

[22] Filed: July 28, 1971 [21] Appl. No.: 167,006

Related 1.1.5. Application Data [62] Division of Ser. No. 776,146, Nov, 15, 1968, Pat. No.

[52] US. Cl. 346/74 ES, 118/637, 346/74 EB, 346/74 P, 355/3 [51] Int. Cl G03g 15/00 [58] Field of Search 346/74 CR, 74 ES, 346/74 EB, 74 P; 355/3; 118/637 [56] References Cited UNITED STATES PATENTS 3,277,818 10/1966 Cone 101/92 3,339,469 9/1967 McFarlane 95/].7

3,582,206 6/1971 Burdige l l 346/74 ES 3,411,482 ll/l968 Brodie 346/74 ES 3,355,289 11/1967 Hall 346/74 P Primary E.raminerTerrell W. Fears Assistant ExaminerStuart Hecker Atmrney-Wilfred G. Caldwell TRANSPARENT ELECTRODE ILLUMINATE I AND CHAKBE r PRE-CORONA l SPRAY [57] ABSTRACT The invention relates to apparatus and methods for constituting or reproducing images through the use of, a multi-layered screen consisting of an array of apertures from facsimile read-out arrangement. A propulsion field directs charged particles through the screen to a receiving medium preferably spaced at a distance from the screen. Charge distribution on the screen controls the flow of particles through the apertures, some of which are in effect blocked, partially blocked, unblocked, and enhanced, depending on the local charge level. Thus, it is possible to produce patterns of varying tone without contact with the printed or effected substrate.

In the facsimile read-out arrangement the electrostatic charge pattern is laid down by a charging stylus through relative movement with the electrostatically chargeable multilayer screen. The screen may be flat or comprise a drum or other configuration and the insulative layer of the screen is preferably substantially non-light sensitive with print out made by passing charged particles through the stylus charged screen in accordance with signal modulation to paper wherein relative motion is established between the screen and paper.

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1. An aperture controlled electrostatic facsimile print-out apparatus employing charged particles for printing information in accordance with received electrical signals comprising, multi-layered apertured carrier means comprising an apertured conductive layer and a coinciding apertured overlaying insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the carrier means for controlling passage of said charged particles in accordance with the patterns to be printed; means for supporting and positioning a print receiving medium spaced from the carrier means at a location therealong; stylus charging means for creating patterns of electrostatic lines of force across the insulative layer in response to the electrical signals; means for establishing relative motion between the carrier means and the print receiving medium to cause the electrostatic patterns to traverse the print receiving medium; and, means for projecting charged printing particles toward the print receiving medium via the carrier means for modulation in accordance with said electrostatic patterns to print said information on said print receiving medium.
 2. The apparatus of claim 1 wherein said insulative layer is characterized by insulation which is substantially light insensitive.
 3. The method of electrostatic facsimile print-out employing charged particles for printing information in accordance with received electrical signals, comprising the steps of: charging a multi-layered apertured carrier having an apertured conductive layer and a coinciding apertured overlaying insulative layer capable of supporting charge potentials of differing magnitude for establishing electrostatic lines of force within the apertures of the carrier for controlling the passage of said charged particles in accordance with the information to be printed, to establish patterns of electrostatic lines of force within said apertures, in accordance with said signals; disposing at least one print receiving medium spaced from the carrier at a location therealong; establishing relative motion between the carrier and the print receiving medium causing the electrostatic patterns to traverse the printing medium; and, directing the charged printing particles toward the printing medium via the carrier for modulation in accordance with said electrostatic patterns to print the information on said print receiving medium.
 4. The method of claim 3 wherein the charging step is carried out by a charging stylus responsive to said signals directly charging the insulative layer which is characterized by substantIally light insensitive insulation. 